Throttle Valve adjustment

[hemi8]

I adjusted my TV cable per GM directions and the shifts just feel a bit soft. So I agjusted it back 1 more click and it shifts nice and firm. Now when I hook up Turbolink and watch the TPS I am not achieving WOT because of the TV cable holding it back just a tad. If I put the cable back to the soft shift setting the throttle works perfectly and the TPS volts are perfect. Is this normal for the TV cable to prevent WOT (creat a binding effect) when set for good firm shifts? Or am I doing something wrong? Intake Set-up, 86 GN, New design Champion intake/plenum, KB 70mm TB.
Mike Freeman

 

[TurboBuRick]

Mine is the same way. Just tryed to find a happy medium.

 

[chris718]

you need to install a 1/8" washer between thetv plunger and the spring . this will correct the problem.

 

[Blazer406]

I adjusted my TV cable per GM directions and the shifts just feel a bit soft. So I agjusted it back 1 more click and it shifts nice and firm. Now when I hook up Turbolink and watch the TPS I am not achieving WOT because of the TV cable holding it back just a tad. If I put the cable back to the soft shift setting the throttle works perfectly and the TPS volts are perfect. Is this normal for the TV cable to prevent WOT (creat a binding effect) when set for good firm shifts? Or am I doing something wrong? Intake Set-up, 86 GN, New design Champion intake/plenum, KB 70mm TB.
Mike Freeman

First..... unless your TV cable is too short..... your condition above is impossible.... if you click it toward the firewall...an extra click or two.... the first time you go WOT (hard to the floor)... it will adjust itself where it is supposed to be.....back out those two clicks you adjusted in.

I will agree that you could click it in a couple clicks (toward the firewall)... and ride around w/o going wide open.... and the shifts should be somwhat firmer... and maybe the shiftpoints are slightly higher..... but by it's own design.... when you have it adjusted too short (toward the firewall).... once you go WOT... it adjusts itself where it needs to be.

Now if your shifts are still too mushy... you need a shift kit and/or bigger servo, etc....or your tranny might soon need a rebuild.

Also... a loose (high stall) converter can really make one feel kinda mushy on the shift....

just my 0.02

 

[mikestertwo]

As mentioned above, add a washer between the throttle valve plunger and the spring. This is a common problem when the engines have mods. The engine is making more power with less throttle opening i.e. larger throttle bodies, porting, etc. so the shifts feel softer. Adding the washer will raise the base pressure in the trans. firming up the shifts and still have enough travel for W.O.T.

 

[hemi8]

The plunger and the spring, do you mean in the tranny where the TV cable connects?
Yes, the engine is very modified, trans is in good solid shape, loose 9.5in converter, big ported GN1's & 70mm TB.
Mike

 

[mikestertwo]

That converter will make the shifts appear soft. The washer goes in the valve body between the plunger and spring that the cable operates.

 

[bsdlinux]

Hell my shifts are way too hard. The previous owner installed a Level 10 kit. But damn the thing shifts hard. I would like hard shifts but only when I'm under WOT or close to it.

Hell at this rate the universal joints will be gone in a year. :frown:

 

[Mad_Trbo]

Is this true

That converter will make the shifts appear soft. The washer goes in the valve body between the plunger and spring that the cable operates.

I never knew a converter could effect the feel of your shifts, is this true?

 

[Blazer406]

I never knew a converter could effect the feel of your shifts, is this true?

sure.... all the slip you get at lower engine speeds cushions the hell out of the shifts.... it isn't until you get higher engine speeds that the converter slips much less and the shifts will apear to have gotten much more firm....

at least that is what makes sense to me.

 

[V6POWER]

What holds this 1/8" washer in place?

 

[mikestertwo]

The washer goes inside the throttle valve sleeve between the spring and the plunger. The spring holds it in place.

 

[V6POWER]

Thanks. Now I see where that was indicated in your previous post. :smile:

 

[77 cruiser]

Valve Body

Goes between 305 & the spring 304 top of pic.

 

[Lee Thompson]

correct me if I'm wrong but

Don't you shim up to the point where there is zero play between # 5 and # 3 With the VB on the bench there is a hole you can look down through and see # 3. Stroke the # 5 plunge and see how far it moves before # 3 moves.--Shim that amount. I thought if # 3 is stroked before throttle is moved that it will raise min. TV above 90 PSI and one problem being second gear starts.

 

[V6POWER]

Jim--Thanks for the picture.

 

[77 cruiser]

Lee, that sounds right.

 

[V6POWER]

Lee--What does #3 and #5 refer to?

 

[chris718]

Shimming Is Done To Preload The Inner Valve And Produce Changes In The Shift Scheduling Which Would Otherwise Be Impoossible With The Combination Of Throttle Body / Carbuerator And Bracketry In Use Because Of Dimensional Design.gm Calculated This By The Cables Starting Point And Amount Of Arc /travel Produced With Given Designs.an Example Is You May Need To Overadjust The Tv To Get Proper Part Throttle Shift Timing But With This Setting You Cant Get A Wide Open Throttle Kickdown Without The Cable Setting The Throttle Body Or Carb From Reaching The Wide Open Position..shimming Allows For Later Part Throttle Shifts With Less Cable Pull Thereby Allowing Mecahanical Wide Open Throttle To Be Reached.is This Making Sense?now Shortening The Tv Spring Would Help If You Were Getting Late Part Throttle Shifts And Loosening The Adjustment Enough To Correct This Didnt Allow The Cable To Pull Out All The Way At Wide Open Throttle Causing The Loss Of Full Throttle Forced Kickdowns Because The Loss Of Pull Doesnt Allow The Port On The Tv Plunger That Produces Forced Detents To Be Opened .

 

[chris718]

lee a mathematical calculation can be used to figure out how much would cause the 2nd start.this also depends on governor exhaust ratio when stationary.usually it take 120 psi to cause this and using different length mtv up springs can alter this point.if the valve body came without out one the addition of it allows the tuner to control the cut in point of shift delay oil much like a power enfrichment system on a carbuerator.these things are usually said to be unfixable,however i know better:biggrin: